A thermoelectric device is a device which uses the thermoelectric effect to convert an electrical voltage to a thermal flux, or to convert a thermal flux to an electrical voltage. Thermoelectric devices are typically solid state devices which take advantage of the Peltier effect and the Seebeck effect to convert voltage to heat flux, and vice versa.
Since they can be used to pump heat, thermoelectric devices can be used as heating or cooling devices. Advantageously, thermoelectric devices can be made very small, so that a thermoelectric device can be used to provide heating or cooling in a small or awkwardly shaped volume. Also, a thermoelectric device need not comprise moving parts, and so may be less likely to suffer a mechanical breakdown than other heating and cooling systems which rely upon fans, pumps or other moving parts. However a thermoelectric device can also be incorporated into a system which uses mechanical parts, such as a fan to create fluid flow and so redistribute heat, if necessary.
UK patent publication number GB2384602 discloses a temperature control device in which a Peltier element can be used to control the temperature of an ink-jet head. A Seebeck voltage is obtained and used by a control means to bring the ink-jet head to a target temperature.
However thermoelectric devices are not immune from breakdown. In particular, a thermoelectric device may become damaged if overheated, and cease to function properly. Therefore it is desirable to be able to monitor thermoelectric devices for damage and, preferably, prevent damage from occurring in the first place. A method or system for detecting a fault in a thermoelectric device, such as an open circuit fault or overheating, would therefore be advantageous.